293
FXUS63 KGRR 081035
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
535 AM EST Fri Nov 8 2024

.KEY MESSAGES...

- Typical Autumn Weather Through Saturday

- Rain Saturday Night into Monday

- Another Period of Rain Next Wednesday/Thursday

&&

.DISCUSSION...
Issued at 225 AM EST Fri Nov 8 2024

- Typical Autumn Weather Through Saturday

It will feel like fall both Friday and Saturday. Mid-level height
ridging slides into the Upper Great Lakes today as a closed low
over the desert southwest ejects to the northeast. This combined
with surface high pressure keeps weather tranquil. With forecast
soundings showing little to no moisture in the profile sunshine
will be plentiful today. Mid to upper-level moisture increases
Saturday ahead of our next system causing increasing mid to high
clouds. Expect highs in the 50s both days with lows tonight in the
mid 20s to low 30s.

- Rain Saturday Night into Monday

Heights will lower in advance of an upper level trough Saturday
night with positive vorticity and warm air advection. Low level jet
convergence picks up around midnight which is when rain is expected
to develop and move in. A few rumbles of thunder are not out of the
question but the best potential will be toward the I-94 corridor.

We could see a break in precipitation late Sunday morning into early
Sunday afternoon before the vorticity maximum associated with the
upper level trough moves over the area through Sunday night. Monday
chances for light showers continue (20 to 30 percent) with the best
chances along the lakeshore. Another shortwave trough and front
moving through Monday will help spread chances across the area
during the afternoon. Total rainfall amounts of a couple tenths to a
half an inch are possible.

- Another period of rain next Wednesday/Thursday

Ridging and high pressure will bring dry and pleasant conditions for
at least Tuesday with highs in the upper 40s to 50s. As previously
mentioned there is some uncertainty with how our next rain maker
will play out. There are timing differences along with how the upper
level trough evolves as it moves across the CONUS. These variations
can be seen in each ensemble`s individual members. That being said,
there is high confidence in rain, but lower confidence in the exact
timing of the rain along with the intensity and potential for
thunderstorms.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 535 AM EST Fri Nov 8 2024

Very high confidence in VFR conditions throughout the TAF period
as skies remain SKC through tonight with a few cirrus arriving by
Saturday morning. West winds today become northerly tonight with
the passage of a low-level boundary. Gusts up to 20 knots are
expected today before subsiding tonight.

&&

.MARINE...
Issued at 225 AM EST Fri Nov 8 2024

Shoreline observations show that the current Small Craft Advisory
is verifying well as gusts up to 30 knots and 3-5 foot waves are
being reported. High pressure moving in will cause winds and waves
to fall in the afternoon and evening hours today. Winds and waves
stay below small craft advisory criteria Saturday with high
pressure overhead. Our next chance for conditions hazardous to
small craft is Sunday as winds increase with the approach of our
next system.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 7 PM EST this evening for LMZ844-845.
     Small Craft Advisory until 3 PM EST this afternoon for
     LMZ846>849.

&&

$$

DISCUSSION...RAH/Thomas
AVIATION...Thomas
MARINE...Thomas